Today, mobile communications are ubiquitous, providing voice and data services via user equipment (UE) that operate on Long Term Evolution (LTE) networks such as mobile handset or smartphone type devices, tablets and laptop computers. Many services using mobile communications involve accurate device position determination of UEs, generally through the use of a Global Positioning System (GPS) or Global Navigation Satellite System (GNSS). For example, the commercial use of positioning has grown tremendously in the last several years. Moreover, GPS-enabled UEs enable emergency services to obtain information as to the position of the UE as part of the processing of an emergency call (E911 services). While position determination for E911 services is mandated by the Federal Communications Commission (FCC), in a number of cases, position determination based on GPS signals is ineffective. In particular, GPS may not be available in certain areas due to blockage of the satellite signals, such inside buildings or other areas where the UE may be unable to detect signals from a sufficient number of GPS satellites. This problem may only increase as the FCC guidelines become more stringent, with 67% of outdoor E911 communications presently mandated to be located with 50 m accuracy and 80% of the calls with 150 m accuracy (rising to 90% by 2020). Moreover, the FCC is proposing to extend E911 location determination to indoor locations and further require vertical location information within 3 m of the caller for 67% of indoor E911 communications (rising to 80% by 2020). Unfortunately, the most recent release (release 12) of the 3rd Generation Partnership Project (3GPP) standard for Long-Term-Evolution (LTE) networks contains updated requirements that serve to undermine position determination.
It would be desirable to provide accurate location determination for 3GPP LTE networks other than by GPS, such as 3GPP LTE networks configured to operate in accordance with release 12 and later releases.